This invention relates to apparatus for and methods of producing a deformed pipe, and especially although not exclusively apparatus for and methods of producing a deformed pipe of thermoplastics material for use in lining pipework, especially for relining underground pipework such as old or leaky sewers, water mains and service pipes for example.
Techniques are known for carrying out relining of such pipework using plastics pipe, such as polyethylene pipe, in which the pipe is reduced in diameter, by deformation either in the production plant, or adjacent the site of relining of the pipework concerned, is inserted in its reduced condition into the pipework, and then expanded to its original size to fit the pipework.
It is also known to effect such reduction in cross section of the pipe by carrying out a deformation longitudinally of the pipe so that the peripheral wall thereof is indented longitudinally to create a generally U-shaped cross section which can be reduced in overall cross-sectional dimension, or even partially flattened and folded over.
It is an object of the present invention to enable the provision of a deformed pipe by simple, effective, and relatively inexpensive means.